1. Field of the Invention
The present invention relates to a device for producing and/or processing panels that includes a transport device for transporting panels along a transport path and a processing device for processing the panels during their movement by the transport device.
2. Discussion of Background Information
Devices of this type are known, for example, in the field of the production of flooring panels for processing the longitudinal and/or transverse sides of the panels. In a known use, a milling tool is used as a processing device, which milling tool embodies or forms a groove on one side of a panel conveyed by the transport device and a tongue corresponding to the geometry of the groove on the opposite side of the panel. The processing of the panels to embody tongue and groove is thereby generally carried out at a plurality of processing stations that are arranged distributed along the transport device and are supplied with panels successively by the transport device.
For the automated sequence of the production and/or processing of panels, in particular for the reliable and precise processing of the panels in the processing devices, it is of vital importance that the panels are conveyed to the processing devices reliably by the transport device with precise and constant position and orientation. With conventional devices for producing and/or processing panels, for example, chain conveyors are thereby used, in which an endless circulating chain is guided along the transport path, the chain links of which on the one hand bear guide parts that are guided in guide rails aligned along the transport path for guiding the chain, and on the other hand bear a bearing area, on which the panel rests. In order to reduce lateral tilting movements of the transported panel out of the horizontal plane, in a known further development of the chain conveyor, the guide parts attached to the chain links are respectively extended on each side perpendicular to the transport direction and guided on two rails running at a distance from one another parallel to the transport direction.
However, in practical use it has been shown with the two known chain conveyors that in particular with the transport of narrower panels or at higher transport speeds, marked deviations from the desired position of the panels occur, which ultimately leads to a faulty processing of the panels in the processing devices or even to a breakdown of the transport and a downtime of the device associated therewith. Furthermore, chain conveyors are structured in a relatively complex manner and, due to high frictional forces between the guide parts and the guide rails, require a relatively high energy expenditure for the drive and high maintenance and repair costs due to wear.
Higher transport speeds can be achieved through belt conveyors, which are likewise used as a transport device in known devices for producing and/or processing panels. In the belt conveyors, two endless belts slide parallel to one another in guide rails that are aligned along the transport path. The belts run in a guide groove of the guide rails, the depth of which is smaller than the height of the belts, so that a panel to be transported can be placed on the sections of the belts lying free, and carried along by frictional contact.
Although the position accuracy of the panels can be increased with the aid of the belt conveyors in particular at higher speeds, conveyors of this type are associated with high acquisition costs, since the guide rails have to be produced in an extrusion process with high precision along their entire length and may not show any deformation at all in particular with local or temporal temperature fluctuations. The guide rails produced for this reason with relatively high material strength are not only expensive and very heavy and cumbersome due to their length and width, they are also unsuitable for transporting narrower panels, since a certain minimum distance is preset between the belts guided parallel due to the width of the rails.
Furthermore, due to the given friction between the belts and the guide rails, a relatively high drive power is necessary for the movement of the belts and a wear of these components is inevitable with longer operation, so that, in addition, the operating costs of the known device are also relatively high. Although it has already been suggested for the known belt conveyors to reduce the friction force between the belts and the guide rails by guiding the belts on an air cushion generated in the guide groove of the guide rails, the provision of corresponding compressed-air devices leads to a further increase in the acquisition and operating costs of the device.
Another known device with which in particular narrower panels are also to be transported, includes only a single endless belt guided along the transport path and a guide bar attached to the transport device next to the transport belt, which guide bar stands up from the transport device in a perpendicular manner and is aligned in the direction of the transport path. The guide bar engages in a longitudinal groove of the panel to be transported, which is inserted in the underside of each panel especially for this purpose.
Although a relatively stable lateral guidance even of narrower panels can be achieved with a guide bar of this type, an additional step of milling the guide groove in each panel is necessary with this solution. If a guide groove of this type is inserted in the underside of a panel, furthermore the counteracting paper applied to the underside of the panel must be cut through, which then to a large extent loses its effect for stabilizing the planar plate form of the panel so that a dishing of the panel occurs due to the tension of the laminate applied to the top of the panel.